using Sandbox.Html;
using System.Collections.Generic;
using System.Linq;

namespace Sandbox.UI
{
	/// <summary>
	/// A container with tabs, allowing you to switch between different sheets.
	///
	/// You can position the tabs by adding the class tabs-bottom, tabs-left, tabs-right (default is tabs top)
	/// </summary>
	[Library( "tabcontainer" ), Alias( "tabcontrol", "tabs" )]
	public class TabContainer : Panel
	{
		/// <summary>
		/// A control housing the tabs
		/// </summary>
		public Panel TabsContainer { get; protected set; }

		/// <summary>
		/// A control housing the sheets
		/// </summary>
		public Panel SheetContainer { get; protected set; }

		/// <summary>
		/// Access to the pages on this control
		/// </summary>
		public List<Tab> Tabs = new();

		/// <summary>
		/// If a cookie is set then the selected tab will be saved and restored.
		/// </summary>
		public string TabCookie { get; set; }

		/// <summary>
		/// If true we will act as a tab bar and have no body.
		/// </summary>
		public bool NoBody
		{
			set
			{
				SheetContainer.Style.Display = value ? DisplayMode.None : DisplayMode.Flex;
			}
		}

		string _activeTab;
		/// <summary>
		/// The tab that is active
		/// </summary>
		public string ActiveTab
		{
			get => _activeTab;
			set
			{
				if ( _activeTab == value ) return;
				_activeTab = value;

				var t = Tabs.FirstOrDefault( x => x.TabName == _activeTab );
				SwitchTab( t );
			}
		}

		public TabContainer()
		{
			AddClass( "tabcontainer" );

			TabsContainer = Add.Panel( "tabs" );
			SheetContainer = Add.Panel( "sheets" );
		}

		public override void SetProperty( string name, string value )
		{
			if ( name == "cookie" )
			{
				TabCookie = value;
				return;
			}

			base.SetProperty( name, value );
		}

		/// <summary>
		/// Add a tab to the sheet.
		/// </summary>
		public Tab AddTab( Panel panel, string tabName, string title, string icon = null )
		{
			var index = Tabs.Count;

			var tab = new Tab( this, title, icon, panel );
			tab.TabName = tabName;

			Tabs.Add( tab );

			var cookieIndex = string.IsNullOrWhiteSpace( TabCookie ) ? -1 : Game.Cookies.Get( $"dropdown.{TabCookie}", -1 );

			panel.Parent = SheetContainer;

			if ( index == 0 || cookieIndex == index )
			{
				SwitchTab( tab, false );
			}
			else
			{
				tab.Active = false;
			}

			return tab;
		}

		public override void OnTemplateSlot( INode element, string slotName, Panel panel )
		{
			if ( slotName == "tab" )
			{
				AddTab( panel, element.GetAttribute( "tabName", null ), element.GetAttribute( "tabtext", null ), element.GetAttribute( "tabicon", null ) );
				return;
			}

			base.OnTemplateSlot( element, slotName, panel );
		}

		/// <summary>
		/// Switch to a specific tab.
		/// </summary>
		public void SwitchTab( Tab tab, bool setCookie = true )
		{
			ActiveTab = tab.TabName;

			foreach ( var page in Tabs )
			{
				page.Active = page == tab;
			}

			if ( setCookie && !string.IsNullOrEmpty( TabCookie ) )
			{
				Game.Cookies.Set( $"dropdown.{TabCookie}", Tabs.IndexOf( tab ) );
			}
		}

		/// <summary>
		/// Holds a Tab button and a Page for each sheet on the TabControl.
		/// </summary>
		public class Tab
		{
			private TabContainer Parent;
			public Button Button { get; protected set; }
			public Panel Page { get; protected set; }
			public string TabName { get; set; }

			public Tab( TabContainer tabControl, string title, string icon, Panel panel )
			{
				Parent = tabControl;
				Page = panel;

				Button = new Button( title, icon, () => Parent?.SwitchTab( this, true ) );
				Button.Parent = tabControl.TabsContainer;
			}

			bool active;

			/// <summary>
			/// Change appearance based on active status
			/// </summary>
			public bool Active
			{
				get => active;
				set
				{
					active = value;
					Button.Active = value;

					Page.SetClass( "active", value );
				}
			}
		}
	}
}